Proteins used as therapeutic agents are typically provided as pharmaceutical compositions that can vary depending on, for example, the properties of the protein and the manner in which it will be introduced into a patient.
Protein instability can be a major difficulty in preparing these pharmaceutical compositions. Unwanted stresses on the protein during preparation of a pharmaceutical formulation can result in unwanted effects such as protein denaturation, precipitation, or adsorption to surfaces.
Pharmaceutical compositions containing bone morphogenetic protein 2 (BMP-2) are of great interest because this protein has been demonstrated to be involved in a variety of biologically important processes such as initiating bone growth and promoting wound healing. For example, BMP-2 has been used to treating or preventing a variety of bone-associated disorders, including those associated with the tibia, maxillofacial, and spinal bone.
BMP-2 is a member of the transforming growth factor-β superfamily. The mature protein is a disulfide-linked homodimer glycoprotein of 32-kilo daltons (kDa). BMP-2 shows limited solubility in water. This limited solubility can hinder attempts to develop pharmaceutical compositions containing this protein.